这是不定方程,解的个数为无穷.如果求正整数解,则有步骤：50x + 40y = 30005x + 4y = 300x = 300/5 - 4y/5 = 60 - 4y/5所以 y 一定能被 5 整除,表示为 y = 5k (k>0)x = 60 - 4k > 0k = 1,2,3.14y = 5,10,15,.70x = 56...